The weights of 4 boxes are 30, 20, 60 and 70 kilograms. Which of the following cannot be the total weight,in kilograms, of any combination of these boxes and in a combination a box can be used only once?
A helicopter flies 80 km North, then it turns West and flies 50 km, then it turns North and flies 120 km, then it turns to its right and flies 50 km. Where is it now with reference to its starting position?
If North is called North west , West is called South west , South is called South east and so on . A person walks straight from South west to North east and then turns left . Walks straight and again turns left . Now at what direction he is facing ?